Magneto



Patented 3, 1931 UNITED TAT S PAT NT OFFICE .m n s'rnu'rnnns, or new YORK, n. 1., Assmnon 'ro nuns A. cute, TRUSTEE meonnro 7' aj neamn filed March 17, 1930. Serial No. 486,553i

This invention relates to magneto ignition. systems. I I

Special objects of theinven'tion are to provide a thoroughly eflicient and practical mag i neto, which will be less. expensive to build and maintain than the ordinary mechanical interrupter type of magneto, and which also willbe less likely to get out of order.

The foregoing and other desirable objects are attained by the novel features of construc- .tion, combinations and relations of parts hereinafter described, illustrated in the accompanying drawings I the claims.

ing 'one'practical commercial embodiment of --breaker units as viewed from the plane of line 2- 12. of Fig. 1; Fig. 3 is a circuitdiagram ofthe device shown in Fig.1; Fig.4 is another circuit diagram illustratingthe provision of a plurality of the breaker units adapted to selectively cut into or out of service.

- Referring Figs l and 3 of the drawings,

it will'be seen that in the present disclosure,

4 the rotating member is in the form of a permanent U-magnet made up' of the branches N and S connected at one end by the backpiece 5 and mounted on the shait 6b means of that back piece and. by means 0 a non-.

magnetic bridge piece 8 at theopposite end. This permanent magnet is shown made up of 35 bolts 9, which serve to hold the assembly, including the end piece 8 in rigid united relation. I Y 1 The field structure comprises in the illustration the pole pieces 10, 11-, Fig. 3, connected at the top by the core piece 12 carrying the primary andsecondar windings 13, 14. The field frame may be oflaminate or solid construction and in the illustration, the parts are shown connected by the screws 15, extendin}; down through the ends of cross-piece 12,

the end portions of the latter being undercut and shouldered as indicated at 16 to fit" closely over the upper ends of the polepieces.

A special and important feature of the inand broadly covered in Fig.1 is a verticalsectional View illustrattransverse laminations connected by through vention is that the break in the rimary circuit is interrupted automatica ly, substan-' tially at the peak of the wave by an. electromagnetic breaker-unit shown generally at 17 in Fig. 1 and-illustrated more in detail in Figs. 2, 3 and 4; These latter views ShOW\. the breaker is made up of an electro-magnetic coil 18 on a magnetic yoke structure 119,the

latter having pole pieces 20, 21, separated to provide a gap 22 with which cooperates an armature 23 carried by a lever 24. This armature lever has a contact portion 25 cooperating with a terminal 26. The breaker contacts areconnectedin the primary cir .cuit by conductor 27 leading from one end of the primary coilto the-stationary breaker point 26,.movable contact 25, armature lever 24, conductor 28to one end of the breaker coil 18 the opposite end of said coil'being suitably grounded as indicated at-29 and the other end of the primary coilbeing grounded as indicated at'30, Fig. 3. 'A condenser 31 is bridged across the breaker points by a short conductor 32 connected with the terminal'33,

the opposite side of said condenser being suitably grounded as indicated'at 33 in Fig. 3. A suitable grounding switch is indicated at 34 in Fig. 3 connected by a conductor 35 with a suitably insulated brush 36 bearing on the terminal 33. This brush is shown in Fig. 1 so as carried by the removable top 37 of the magneto casing, so' that the removal of this top interrupts the control circuit of the magneto.

' The armature oif the electro magnejtic in- 86 terrupter may be suitably tensioned to respond only to the peak or other desired sec- 1 tor of the current wave, the meansfor the purpose-being shown as a'compression spring 38 held engaged with the armature by a head- 9c ed'screw 39, whose position can be set by a nut 40, Fig.2, the latter being accessible through an opening. 41 in the top of the case.

' The secondary circuit of the magneto is il- 9t ated; from the magneto shaiit loy the usual two to-one gearing 4,8,

breakers. The extra breaker points are-indicated at 25a, 26a and they are shown oper ati'ng in conjunction with the magnetic gaps 22p similar to the gaps .22 but located at the opposite ends of the eIectro-magnetic'units. In this'particular case, the lead 27 from the primary of the magneto passes through the. arm 49 ofthe selector switch and thence by way of any one-of the switch contacts .50, 5.1, 52 and 53, through leads27a, 276, 270, 27

to the four breaker contacts. I

. The. selector switch/l9 may, be located. at any convenient control point onthe aircraft orother'vehicl'e on which the magneto is used, so that in case 'of any failure or indication of .failure of the magneto, anew interrupter may be instantly switched into operation. The condensers are preferably combined or built into. the magnetic breaker units as by being located between the arms of the magnetic yoke (Fig. 2), so that in switching over,

a new condenser will be brought into service.

. If desired, 0ne condenser may be made to' v servefor both the sets of a double ended f breaker'unit, as indicated in Fig. 4, by connecting them through leads 32a direct to the line 27, instead of through theswitch buttons 50,51, etc.. r f a I .Constructed as disclosed, the magneto'can be produced quite inexpensively, 'sinc'eithere are: no cams, mechanically actuated breaker arms or othernecessarily accurate and more orless'd'elicate parts. The. instant of'break and hence the timing is determined autoandbreaker structures, with'the short elec- .trical connections are all disposed in the upper chamber 54 above the horizontal partition 55, which separates the lower rotor chamher from the upper space. Consequently,

any difiiculty with the transformer coil, the

breaker mechanism or the connections, may be quickly remedied upon removal of the top cover 37, The magnetic breaker unit, or

units, if there be more than one, may be re movably fastened down in the upper chamher as by means of the screw fastenings indicated at 56.

whatis claimed is:

comprising a'rotating permanent magnet, a field structure .in cooperative relation there with and including a coil, an electromagnet connected in series relation with said coil, :1

circuit breaker for said coil actuated bysaid said circuit'breaker to interrupt the coil circuit at the desired point inthecurrent wave generatedpby the magnetol lelectromagnet and meansifor variably setting 2. In electric ignition systems, the combination'of a magneto including relatively rotatable parts, one carrying primary and secy ondary coils, an felectromagnet. connected in series relation with said primary coil, a circuit breaker actuated by. said electr'omagnet andconnected to control the primary coil circuit and means for variably setting said circuit breakerto operate at a desired level of the" current wave generated by the mag 'neto.' I

, 3. A magneto comprising a rotating permanentmagnet, a field structurein'cooperative relation therewith andi ncluding primary' and secondary w nd ngs, a circuit breaker connected to interrupt the circuit of I said primary coil, anlelectromagnet for ac'tuating said circuit breaker and connected in series relation with the primary co l and means for variably setting said circuit breaker to operate at a desired level ofthe current wave generated bythe magneto.

4. A magneto comprising a rotating per- 'manent magnet, a fieldstructure in cooperative relation therewith and including pri-i mary and secondary windings, acircuit breaker connected to interrupt the circuit of said primary coil, an electromagnet for. ac-

tuating said circuit breaker and connected in seriesrelation with the, primary coil, means for variably setting said circuit breaker to operate at a desired level of thecurr'ent wave generated by the magneto including a spring governing action of the circuit breakerb the electromagnet and an .ad'ustable device a for varying theforce exerted y 'said'spring.

, matically by the force of current generated in the machine and this timing is accurately determinable by varying the tension on the magnetically actuated breaker arm; The coil 5. A magnetocomprising a case having lower' and upper compartments, the upper ain-electromagnetic circuit breaker also removably. mounted in the upper compartment connected with the transformer windings,

whereby upon removal of thecover the transformer windings and electromagnetic cir-' cult breaker are accesslble for removal.

. .6; A- magneto comprising cooperating field and rotor struciureapa plurality of electromagnetic circuit breakers closely associated with the field structure and a remotely located control switch for selectively cutting vice relation with the field tendinglongitudina'llyofthesame,

' magnetic circuit brea cuit of the primary winding and connected breakers into serstructure.

7. A magneto having transformer windings, electromagnetic circuit breakers for controlling the primary of the transformer windings and means for selectivel cutting said electromagnetic circuit brea ers into service relation.

8. In combination, a magneto having primary and secondary windings, electromagnetic circuit interrupters for. the primary the electromagnetic circuit winding and means for interchangeably and selectively switching said electroma etic circuit interrupters into series re ation with said'primary winding. y

9. A magneto comprising a permanent U- magnet mounted formotation on an axis ex pole pieces about the legsof said U-magiiet, primary and secondary windings electrically associated Y with said pole pieces and an electro-magnetic circuit breaker controlling the circuit of the primary winding and connected to be actuated by the current winding.

10. A magneto comprising a permanent U- magnet mounted for rotation on an axis extending longitudinally of the same, pole pieces about the legs of said U-magnet, primary and secondary windings electrically associated with said 1pole pieces, an electrogenerated in said primary to be actuated by the current generated in said primary winding andincluding a breaker element and adjustable spring means I ing said breakers er controlling the cirdensers into and out of-service relation to the primary winding.

16. A magneto havi an electromagnetic breaker unit provided with two independent ly operating circuit breakers and means for selectively cutting said independent circuit breakers into and out of service relation.

.17. A magneto havin an electromagnetic breakerunit provided with two inde ndently.operating circuit breakers, means or selectively cutting said independent circuit breakers into and out of service relation and a condenser connected in operative relation with both circuit breakers and therefore effective when either circuit breaker is in service. 18. A magneto havingan electroma etic breaker unit provided with magnetically operated breakers at opposite ends of the same and means for independently switchinto and out of service relation.

In'testimony whereof I afiix m si nature.

JOSHUA STRU I RS.

1 for variably predetermining the timing 'of operation of said breaker. Y I

11. A magneto, comprising a field structure having pole pieces andp'rovided with primary and secondary windings, a permanent U-magnet arranged to rotate between the pole pieces on an axis extending longi-' tudinally of the same, said U-ma net being rotatably supported at both ends and an electromagnetic interrupter for theprimary winding connected to be electrically actuated bythe current generated in the primary rotation of said U-'magnet.

12. A magneto having a current generating winding, an electromagnetic breaker for said winding connected to be electrically actuated thereby, condensers andswitch means for interchangeably connecting said condensers in service relation 13. A magneto having a current generating winding, a plurality of breakers for said winding, a plurality of condensers and switch means for interchangeably connecting said breakers and condensers inservice relation to r the winding.

- 14. A magneto having a current generating winding, a plurality of condensers associatedwith said winding and means for selectively switching said condensers individually to said winding. 

